It's a little disconcerting that an external group of people can literally make the internet crawl to a halt. I didn't think that was feasible.

They are using a DNS reflection attack

A DNS amplification attack (aka DNS reflection attack) is a type of distributed denial of service (DDos) attack that takes advantage of the fact that a small DNS query can generate a much larger response. When combined with source address spoofing, an attacker can direct a large volume of network traffic to a target system by initiating relatively small DNS queries.

The amplification factor in this type of attack depends on the type of DNS query and whether or not a DNS server (used as a middleman in the attack) supports sending large UDP packets in a response, which is a feature intended to optimize DNS communications. If a DNS server does not support large (>512 bytes) UDP packets in a response, it can revert to TCP. This reduces the effectiveness of an amplification attack because TCP is much less vulnerable to source address spoofing.

Its not that big a deal, its only Spamhaus that are really feeling the pain of it. Pretty much everyone else shouldn't notice anything

The media is hyping it up, much like how the internet survives an earthquake. Its the internet, lots of interconnected nodes, if one bit breaks (which happens almost daily) the rest carries on until that bit comes back - look up BGP for more information about routing on the internet.

Worst case scenario is that a link between one location and another that has no redundancy goes down, in which case that part is cut off from the rest until service is restored. In the case of this Spamhaus attack it might mean a website is responding a bit slower as the traffic on a particular link is heavy, but you will only really notice if you are accessing something over one of those links.
Most likely people in America haven't noticed a thing especially if they are only accessing local US websites